An electrocardiogram records a change in a voltage by installing a sensor on a skin around a heart. The voltage measured by the sensor installed on the skin has an analog characteristic. A general method of measuring an electrocardiogram is a method of measuring a change in a voltage by using a potential difference measuring method to measure a fine voltage.
However, when it is necessary to enlarge an electrocardiogram graph in order to obtain fine information, most of the electrocardiogram measuring equipment in the related art directly increases a potential difference to obtain a more precise result. However, it is impossible to unlimitedly increase a potential difference, and when a potential difference is increased, a phenomenon, in which a current reversely flows, may occur due to a potential difference with a body.
Further, existing electrocardiogram equipment is configured so that one equipment uses the predetermined number of leads. However, when a predetermined lead is not attached onto a body for each equipment, there is a problem in that it is impossible to read a measured electrocardiogram signal or obtain necessary information.
Further, the existing electrocardiogram equipment adopts a fixed unit recording method according to a time order, so that it is very inconvenient to variously make a search according to a situation. Accordingly, in order to search for stored material in electrocardiogram equipment capable of storing materials, it is necessary to inconveniently search for the material according to a recorded order.
In order to solve the problem, an implantable electrocardiogram sensor, which is directly transplanted or implanted into a human body to more accurately measure a signal, has been developed, but the implantable electrocardiogram sensor needs to continuously transmit a signal for 24 hours, so that there is a problem in that a capacity of a power supply needs to be large, and when a large capacity battery is used in order to solve the problem, the implantable electrocardiogram sensor has a large size, so that an extensive surgical operation needs to be performed in order to implant the implantable electrocardiogram sensor into the human body.